Basically, keep your mind and body busy.
Getting over someone just takes a bit (or a bit more) time. Invest the time into something cool or useful. It can be anything, from learning a new skill or language through planting stuff - all over to painting your room or renovating your kitchen :-3 Just pick a project you fancy. Hang out with your friends/family as much as possible; surround yourself with people you like. Strike up new conversation/s with new person/s you find interesting. In the evening (if you aren't out) play your game or read a book or watch a movie/show.
Stay out of her social media profiles, if possible just stay out of the social media she uses altogether :-) At least for a while.
Don't drink much, because you'll want to call/text her. When you feel the need to contact her take some deep breaths and count to 10 whilst thinking "nothing good is gonna come out of this" and if that doesn't help slap yourself across the face a few times or go take a shower.
But anyway, nothing's hard as it may seem to.